Ducted-fan air-vehicles are known for their superior stationary aerodynamic hovering performance, three-dimensional precision position hold, low speed flights, and precision vertical take-off and landing (VTOL) capabilities. In addition, the duct provides protection from contact with the rotating fan blade close in operations.
As such, ducted-fan air-vehicles, and in particular, unmanned aerial vehicles (UAVs) implementing ducted-fans, are increasingly being deployed in battlefield scenarios. For instance, typical UAV operations may include reconnaissance and surveillance, navigating for troops and ground vehicles, and non-line of sight targeting. Accordingly, a UAV may be configured to detect enemy troops and vehicles in areas where ground forces (or even aerial forces) lack a direct line-of-sight. In effect, UAVs may become “sentinels” for troops as they move into enemy territory.
Ducted-fan UAVs may be designed to perform autonomous missions that generally require the UAV to launch vertically, fly along a pre-planned flight plan, and land vertically. For example, at some point while flying a mission, the ducted-fan UAV may be expected to perform “perch and stare” observations. Perch and stare observations require the UAV to land vertically, perform observations (possibly for an extended period of time with engine shutdown), and takeoff vertically. To control the direction of flight ducted-fan UAVs are generally equipped with vanes that serve to create control moments generated by deflecting the high speed air flow exiting the ducted fan.